From the Magazine

Supertyphoon Ferocity Clues Found in Western Pacific

Data collected by satellites and floating probes have chronicled a 2-decade rise in the temperature and thickness of a layer of warm subsurface ocean water east of the Philippines. These warmer subsurface waters along supertyphoon Haiyan's track fueled its fury. Meanwhile, strong easterly trade winds have pushed warmer water to the western North Pacific, raising sea level in the region. This phenomenon amplified Haiyan's storm surge and accounts for the largest share of the typhoon's death toll.